Fault protection and fault-tolerant operation method for matrix converter-induction motor system

Matrix converter has no free-wheeling path, which makes its fault protection a difficult problem. This paper proposes a new fault protection method for matrix converter-induction motor system. The key of the proposed method is to provide a controlled path for the motor to release the stored energy in fault cases. The path is selected to brake the motor as soon as possible. Besides, by reconfiguring the converter-motor system, a fault-tolerant operation mode is deduced. The validity of the proposed method is analyzed under three conditions, namely motor overload, switch open-circuit and short-circuit faults. The validity and the efficiency are verified by the simulation and experiments.